[Image] CurveBS for PolarFS dev image

[mrdrivingduck]

Previously, PolarDB for PostgreSQL uses a CentOS 7-based development image, whose software stack is too old, and the Curve for PFS image uses this image as base image, too.

Recently, I have updated the base image of dev image to Ubuntu 20.04. I strongly recommend to use this image as a base image for CurveBS for PFS, since the SDK of Curve is Debian-based, so that we can use the software package from APT instead of building from source, saving the building time of image. Again, an AMD64/ARM64 multi-architecture image is needed, because PolarDB supports both arch.

PR should be raised to this repo, thx~